Volatile disinfection by-product analysis from chlorinated indoor swimming pools

William Alan Weaver, Purdue University

Abstract

The disinfection of indoor swimming pools through chlorination is of growing concern, in part due to the generation of problematic disinfection by-products (DBPs). To examine the scope of this issue, eleven pools were sampled over a six month period and analyzed for their volatile DBP content. Eleven compounds were identified as volatile DBPs: cyanogen chloride (CNCl), cyanogen bromide (CNBr), dichloroacetonitrile (CNCHCl2), dichloromethylamine (CH3NCl2), chloroform (CHCl3), bromoform (CHBr3), dichlorobromomethane (CHBrCl2), dibromochloromethane (CHBr 2Cl), monochloramine (NH2Cl), dichloramine (NHCl2), and trichloramine (NCl3). Of these eleven compounds, ten were identified as regularly occurring, with dichlorobromomethane only (CHBrCl2) only appearing sporadically. Pool water samples were analyzed for residual chlorine (DPD colorimetric method) and by membrane introduction mass spectrometry (MIMS). These two methods were chosen as complementary measures of residual chlorine, and to allow for comparisons between the methods. The DPD method was determined to overestimate inorganic chloramine content in swimming pools as compared to MIMS. Additionally, dichloromethylamine and dichloroacetonitrile were identified through statistical analysis as potential swimming pool water quality indicator compounds. Lastly, air sampling for trichloramine was performed in one aquatic facility containing 3 pools, where swimmer-induced turbulence was determined to play a significant role in volatization. Through this research, volatile DBPs from chlorinated swimming pools were identified, correlations between individual DBPs and residual chlorine were developed, and the compatibility of multiple analytical methods used for evaluating both air and water quality was examined.

Degree

M.S.

Advisors

Blatchley, Purdue University.

Subject Area

Environmental Health|Environmental engineering

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